Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/24—Heart valves ; Vascular valves, e.g. venous valves; Heart implants, e.g. passive devices for improving the function of the native valve or the heart muscle; Transmyocardial revascularisation [TMR] devices; Valves implantable in the body
  • A61F2/2442—Annuloplasty rings or inserts for correcting the valve shape; Implants for improving the function of a native heart valve
  • A61F2/2445—Annuloplasty rings in direct contact with the valve annulus
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/24—Heart valves ; Vascular valves, e.g. venous valves; Heart implants, e.g. passive devices for improving the function of the native valve or the heart muscle; Transmyocardial revascularisation [TMR] devices; Valves implantable in the body
  • A61F2/2442—Annuloplasty rings or inserts for correcting the valve shape; Implants for improving the function of a native heart valve
  • A61F2/2445—Annuloplasty rings in direct contact with the valve annulus
  • A61F2/2448—D-shaped rings
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/24—Heart valves ; Vascular valves, e.g. venous valves; Heart implants, e.g. passive devices for improving the function of the native valve or the heart muscle; Transmyocardial revascularisation [TMR] devices; Valves implantable in the body
  • A61F2/2442—Annuloplasty rings or inserts for correcting the valve shape; Implants for improving the function of a native heart valve
  • A61F2/2466—Delivery devices therefor
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2230/00—Geometry of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
  • A61F2230/0063—Three-dimensional shapes
  • A61F2230/0091—Three-dimensional shapes helically-coiled or spirally-coiled, i.e. having a 2-D spiral cross-section
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2250/00—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
  • A61F2250/0014—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis
  • A61F2250/0018—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis differing in elasticity, stiffness or compressibility

Definitions

• the present invention relates generally to cardiac implants and particularly to flexible annuloplasty rings especially for use in non- traditional surgeries.
• Prosthetic annuloplasty rings are used to repair or reconstruct damaged or diseased heart valve annuluses.
• the heart is a hollow muscular organ having four pumping chambers: the left and right atria and the left and right ventricles, each provided with its own one-way valve.
• the natural heart valves are identified as the aortic, mitral (or bicuspid), tricuspid and pulmonary, and are each mounted in an annulus comprising dense fibrous rings attached either directly or indirectly to the atrial and ventricular muscle fibers. Each annulus defines a flow orifice.
• valve repair techniques including quadrangular segmental resection of a diseased posterior leaflet, transposition of posterior leaflet chordae to the anterior leaflet, valvuloplasty with plication and direct suturing of the native valve, substitution, reattachment or shortening of chordae tendinae, and annuloplasty in which the effective size of the valve annulus is contracted by attaching a prosthetic annuloplasty ring to the endocardial surface of the heart around the valve annulus.
• An annuloplasty ring is designed to support the functional changes that occur during the cardiac cycle:
• the annuloplasty techniques may be used in conjunction with other repair techniques.
• the rings either partially or completely encircle the valve, and may be rigid, flexible, or selectively flexible.
• Such minimally invasive procedures usually provide speedier recovery for the patient with less pain and bodily trauma, thereby reducing the medical costs and the overall disruption to the life of the patient.
• a minimally invasive approach also usually results in a smaller incision and, therefore, less scarring, which is an aesthetic advantage attractive to most patients.
• minimally invasive heart surgery offers a surgical field that may be only as large as a resected intercostal space or a transversely cut and retracted sternum. Consequently, the introduction of tools, such as prosthetic sizing elements, valve holders, annuloplasty ring holders, and other such devices, becomes a great deal more complicated.
• the present application provides an annuloplasty ring comprising an inner core member extending around the entire periphery of the ring in either a closed or open shape.
• the inner core member has a majority of its length with a first elastic modulus sufficiently flexible to enable the core member to be compressed from its relaxed ring shape into a narrow shape suitable for passage through a tubular access device.
• the inner core member further includes a plurality of discrete control points located at spaced apart locations, the control points creating localized regions of higher elastic modulus than the first elastic modulus.
• annuloplasty ring comprising a flexible core member extending around the entire periphery of the ring in either a closed or open shape, the flexible core member having a first elastic modulus.
• a plurality of discrete control points is located around the flexible core member at spaced apart locations. The control points create localized regions of higher elastic modulus than the flexible core member and at least one control point is bent to control the shape of the core member.
• Another annuloplasty ring disclosed herein includes a flexible braided cable extending around the entire periphery of the ring in either a closed or open shape.
• a plurality of discrete control points located around the flexible braided cable at spaced apart locations creates localized regions of higher elastic modulus than the flexible braided cable.
• the flexible braided cable preferably comprises a multi- stranded braided cable.
• the braided cable comprises strands of at least two different metals braided together.
• a still further annuloplasty ring of the present application has an inner core member extending around the entire periphery of the ring in either a closed or open shape.
• a majority of the length of the inner core member has a first elastic modulus sufficiently flexible to enable the core member to be compressed from its relaxed ring shape into a narrow shape suitable for passage through a tubular access device.
• the inner core member further includes a plurality of discrete control points located at spaced apart locations, the control points creating localized regions of higher elastic modulus than the first elastic modulus.
• the annuloplasty rings disclosed herein may have a flexible core member comprises a multi- stranded braided cable.
• the multi-stranded braided cable has at least seven braided cables in cross-section.
• an annuloplasty ring is shaped for implant at the mitral annulus and has a convex posterior portion and a relatively straight anterior portion, and wherein there are at least three control points. Preferably, there is a control point centered on a minor axis of the ring in the posterior portion.
• annuloplasty ring shaped for implant at the tricuspid annulus there are at least three control points.
• control points may comprise tubular members extending at least 3 mm in length crimped to the flexible core member.
• control points each comprises a coiled wire extending at least 3 mm in length and helically wrapped around the flexible core member.
• control points comprise regions of the a flexible braided cable that are welded, soldered, polymer overmolded or adhered to be stiff er than adjacent regions of the flexible braided cable.
• a multi-stranded cable replaces solid core wire for both the tricuspid and mitral valves. Cable allows for greater deployment flexibility for minimally-invasive surgical (MIS) implant, while still maintaining the required strength and similar tensile properties of solid-core wire.
• MIS minimally-invasive surgical
• selective placement of point- welds or other such control points locally control other parameters such as the amount and direction of displacement as the ring undergoes external loading.
• Cable with well-placed control points result in a MIS annuloplasty ring with sufficient flexibility in the x-y plane to allow a surgeon to squeeze the ring into a 1cm X 1cm incision, while maintaining structural rigidity under forces exerted on the implanted ring by the cardiac cycle and allowing for asymmetrical deflection to be designed into the product.
• Figures 1A and IB are plan and elevational views, respectively, of an exemplary inner core member having a braided cable and control points for an open mitral annuloplasty ring;
• Figures 2A and 2B are plan and elevational views, respectively, of an exemplary inner core member having a braided cable and control points for a closed mitral annuloplasty ring;
• Figures 3A and 3B are plan and elevational views, respectively, of an exemplary inner core member having a braided cable and control points for a closed asymmetric mitral annuloplasty ring;
• Figures 4A is a partially cutaway plan view of an exemplary closed mitral annuloplasty ring with a core member similar to Figures 2 A and 2B, while Figure 4B is an isolated view of the cable used in the core member and Figure 4C is a cross-section though the ring at a control point;
• Figure 5 is a schematic view of the core member from the ring of Figure 4A squeezed into an elongated shape and passed through a delivery tube;
• Figures 6A and 6B are elevational and plan views, respectively, of an exemplary inner core member having a braided cable and control points for an open tricuspid annuloplasty ring;
• Figures 7A and 7B are schematic views of the core member from Figure 6A opened into an elongated shape and passed through a delivery tube;
• Figures 8A-8C are perspective, plan and elevational views, respectively, of an exemplary inner core member having a braided cable and control points for an alternative open tricuspid annuloplasty ring;
• Figures 9-12 are pairs of drawings illustrating a simulated force application to a mitral annuloplasty ring having varying numbers and locations of control points;
• Figures 13-16 are pairs of drawings illustrating a simulated force application to a tricuspid annuloplasty ring having varying numbers and locations of control points;
• Figures 17A-17G show a number of different possible braided cable configurations that may be used
• Figures 18A-18C are side, posterior, and top plan views, respectively, of a still further alternative flexible open annuloplasty ring with control points;
• Figures 19A-19C are side, posterior, and top plan views, respectively, of a still further alternative flexible open annuloplasty ring with control points;
• Figures 20A-20C are side, posterior, and top plan views, respectively, of a still further alternative flexible open annuloplasty ring with control points;
• Figures 21A-21D are schematic views illustrating a distal end of a tubular delivery system having a guide wire that may be used for implanting an open annuloplasty ring of the present application;
• Figures 22A-22C are sectional views through the distal end of alternative tubular delivery system having a different guide wire used for implanting an open annuloplasty ring of the present application;
• Figures 23A-23C are schematic views of the distal end of a tubular delivery system having a corkscrew-shaped guide wire for deploying an open annuloplasty ring of the present application;
• Figure 24 is a partial sectional view of a still further alternative annuloplasty ring delivery system having a two-part delivery tube and a pusher;
• Figure 25 is a schematic view of the distal end of an alternative tubular delivery system in which an annuloplasty ring of the present application is deployed by peeling away one side of a delivery tube. Description of the Preferred Embodiments
• annuloplasty ring or repair segments refers to any generally elongated structure attachable to the inner native valve annulus and used in annulus repair, whether straight or curved.
• annuloplasty ring is conventionally understood to provide either a complete or substantially complete loop sized to correct a misshapen and/or dilated native annulus and which is sutured or otherwise attached to the fibrous annulus from which the valve leaflets extend.
• a partial ring or even a straight repair segment may be used around just a portion of the annulus, such as around the posterior edge.
• FIGs 1A and IB A first embodiment of the present invention is illustrated in Figures 1A and IB in which a core member 20 for a flexible mitral annuloplasty ring defines a posterior portion 22 and an anterior portion 24.
• the core member 20 resembles an open D-shape with the outwardly convex posterior portion 22 and a substantially straight anterior portion 24 extending generally between commissures, or possibly the trigones, of the annulus.
• An annuloplasty ring that includes the core member 20 may also have a suture -permeable outer covering (not shown), such as a silicone tube surrounding the core member 20 which is then surrounded by a fabric tube.
• the suture-permeable covering provides anchoring material through which to pass sutures for attaching the annuloplasty ring to the annulus.
• the traditional construction is seen in Figures 4A and 4C.
• the present application contemplates a number of embodiments of core members 20, and it will be understood that any outer coverings known may be used.
• the mitral valve includes a relatively large posterior leaflet and smaller anterior leaflet, both of which attach at their outer peripheries at the mitral annulus.
• the conventional representation of these two leaflets shows the posterior leaflet below the anterior leaflet, with their line of coaptation, or contact in the flow stream, as a smile-shaped curve.
• the mitral valve commissures define distinct areas where the anterior and posterior leaflets come together at their insertion into the annulus - which can be imagined as the corners of the smile-shaped coaptation line.
• the anterior portion of the mitral annulus attaches to the fibrous trigones and is generally more developed than the posterior annulus.
• the right fibrous trigone is a dense junctional area between the mitral, tricuspid, non-coronary cusp of the aortic annuli and the membranous septum.
• the left fibrous trigone is situated at the junction of both left fibrous borders of the aortic and the mitral valve. Although the trigones and commissures are proximate to each other, they are not at the exact same location.
• the exemplary core member 20 comprises a flexible cable 26 having a plurality of discrete control points or members 28-30 thereon.
• the control points may take a number of configurations, but act to rigidify and define the shape of the core member 20.
• the control points 28-30 comprise tubular sleeves or crimps squeezed onto the flexible cable 26 at select locations.
• two anterior crimps 28 are provided at approximately the locations at which the commissures of the mitral annulus are located, or in other words at the end boundaries of the anterior aspect or anterior leaflet.
• the two anterior crimps 28 are curved and preferably metallic so as to be mechanically squeezed and deformed tightly around the cable 26.
• the cable 26 thus assumes corners at the location of the anterior crimps 28.
• two intermediate crimps 30 help shape the cable 26 into the preferred D- shape.
• the core member 20 is desirably symmetric about a minor (vertical) axis such that the crimps 28, 30 are located symmetrically across from their counterparts.
• the core member 20 has a single posterior crimp 32 in the middle of the posterior portion 22.
• the core member 20 includes two free ends 34 separated across the minor axis in the middle of the anterior portion 24. As seen in Figure IB, the anterior portion 24 bows upward from a plane in which the posterior portion 22 lies, such that the free ends 34 project upward toward each other.
• the core member 20 when in its relaxed, unstressed state is shaped the same as a Carpentier-Edwards® Classic® Annuloplasty Ring available from Edwards Lifesciences of Irvine, CA.
• the open nature of the core member 20, and annuloplasty ring formed thereby permits a surgeon to open the structure up into an elongated strand for delivery through a small tube such as a catheter or cannula.
• the core member 20 comprises a substantially elastic construction that permits it to be elongated and stressed from its relaxed shape as shown into a linear configuration for delivery through an access tube.
• the rings described herein thus have a relaxed or unstressed shape and a stressed delivery shape.
• the unstressed shape as shown in the drawings generally describes the shape after implant, though external forces from the surrounding annulus may deflect the unstressed shape a little. Desirably there is a balance between permitting the ring to elongate for delivery while at the same time being able to remodel to a certain extent the particular annulus consistent with the relaxed shape.
• Conventional remodeling rings include a more rigid core, such as solid titanium, while wholly flexible rings are typically formed of silicone, neither of which would be suitable for the present purpose.
• FIGS 2A and 2B A second embodiment of the present invention is illustrated in Figures 2A and 2B in which a core member 40 for a flexible mitral annuloplasty ring defines a posterior portion 42 and an anterior portion 44.
• the core member 40 resembles a D-shape with the outwardly convex posterior portion 42 and a substantially straight anterior portion 44.
• the core member 40 has a closed peripheral shape.
• An annuloplasty ring that includes the core member 40 may also have a suture-permeable outer covering (not shown), such as a silicone tube surrounding the core member 40 which is then surrounded by a fabric tube, such as seen in Figures 4A and 4C.
• the closed mitral core member 40 features the same number and location of control points or members as in the open ring above.
• the core member 40 is formed by a braided cable 46 having two symmetric anterior control points 48, two symmetric intermediate control points 50, and a single posterior control point 52 centered on a minor axis of the D-shape.
• the control points are again illustrated as tubular crimps, though as will be explained below other configurations are possible.
• Figure 2B shows the core member 40 in elevational view illustrating an anterior bow 54.
• the core member 40 when in its relaxed, unstressed state desirably has the same shape as the Carpentier-Edwards® Physio® Annuloplasty Ring available from Edwards Lifesciences.
• a core member 60 for a flexible mitral annuloplasty ring defines a posterior portion 62 and an anterior portion 64.
• the core member 60 has a modified D- shape with the outwardly convex posterior portion 62 being pulled in on the right side so as to be asymmetric.
• the core member 60 has a closed peripheral shape, but in this embodiment in its unstressed state mimics the shape of the Carpentier-McCarthy-Adams IMR ETlogixTM Annuloplasty Ring, also available from Edwards Lifesciences.
• the core member 60 includes four discrete control points or members 68, 70, 72, 74 around the periphery at strategic locations.
• a first anterior control point 68 is located, when implanted, at one of the commissures of the mitral annulus, and a second anterior control point 70 is at the other commissure.
• the anterior control points 68, 70 provide some rigidity for the core member 60 and also bend the flexible cable 66 at the opposite anterior corners.
• a first posterior control point 72 provides rigidity and curves the cable 66 on the left side in plan view, while a second posterior control point 74 is located on the right side in a pulled-in region.
• Figure 3B shows the right side of the posterior portion dipping downward at 76, and the control point 74 desirably shapes the cable 66 in this area.
• an annuloplasty ring 80 comprises a core member that resembles the core member 40 of Figure 2A, and includes a closed length of braided cable 82 and a plurality, in this case five, discrete control points or members 84.
• This annuloplasty ring 80 in its relaxed, unstressed state is shaped to mimic the Carpentier-Edwards® Physio IITM Annuloplasty Ring available from Edwards Lifesciences. Although not shown in elevation, the Physio IITM ring has more pronounced upward bows on both the anterior and posterior sides. Also, the larger ring sizes of the Physio IITM ring become less D-shaped and more circular to better correct for pathological changes in mitral annular dimensions seen in larger patients.
• Figure 4B shows a short length of the braided cable 82, which includes seven strands of wire including a central wire and six strands wound helically therearound.
• This construction is also known in the art as a simple 1x7 cable, having a single winding of seven wires.
• Other cable constructions are also possible, such as 1x3 or 1x19 simple braids.
• the core members will include flexible cables having multi strand braids, such as 7x7, 7x19, 19x7 or even 7x7x7 braided cables.
• Each of these possible braid constructions is seen in Figures 17A-17G, and will be described in greater detail below.
• Figure 4 A shows an outer fabric cover 86 which has been cut away to illustrate a portion of the inner core member.
• Figure 4C shows a preferred cross-sectional layout, with the fabric cover 86 surrounding a suture- permeable interface 88, such as a silicone rubber tube.
• the interface 88 closely surrounds the control point 84, which in the illustrated version is a crimped tube.
• the braided cable 82 Inside the crimp 84 is the braided cable 82.
• Figure 5 schematically illustrates the core member of the
• annuloplasty ring 80 squeezed into an elongated shape to fit within a tubular access device 90.
• the flexible cable 82 facilitates the conversion from D-shaped to linear so that the ring 80 may be introduced to an implant site through the access device 90.
• the access device 80 may be a cannula or introducer tube, or other similar expedient.
• This delivery method is enabled by the multi-stranded cable 82 which has the flexibility to accommodate large amounts of bending without permanent deformation.
• the disadvantage of cable is that it is not as easy to
• control points 84 at discrete locations on the cable 82 where a defined bend is desired.
• control points might be precise spot- welds on the cable ring, but in the illustrated embodiment small steel pins or tubes are crimped or wrapped around a section of cable 82 and bent to the desired curvature.
• Figures 6A and 6B show a still further core member 100 in the shape of a tricuspid annuloplasty ring. As in the earlier embodiments, exterior components such as a silicone interface and fabric cover are not shown to better illustrate the flexible core member 100.
• the core member 100 when in its relaxed, unstressed configuration is the same shape as an Edwards MC 3 Annuloplasty System available from Edwards Lifesciences.
• the core member 100 includes a flexible braided cable 102 having two free ends 104a, 104b. A series of discrete control points or members 106, 108, 110, 112, 114 provide rigidity and shape the cable 102.
• the core member 100 has the classic tricuspid shape in plan view, starting at the first free end 104a and extending in a clockwise direction around a first segment corresponding to the aortic part of the anterior leaflet in which two control members 106, 108 are located. Adjacent to the first segment is a second segment corresponding to the remaining part of the anterior leaflet in which is located a third control member 110, the second segment ending at the postero septal commissure and a fourth control member 112.
• a third segment extends from about the fourth control member 112 to the second free end 56b, which is mid- way along the septal leaflet, and includes a fifth control member 114.
• the nomenclature for these segments is taken from the standard anatomical nomenclature around the tricuspid annulus.
• each of the control members 106, 108, 110, 112, 114 provides both rigidity and shape to the core member 100.
• the control members 106, 108, 110, 112, 114 all provide the convex curvature in plan view, and also induce the vertical deflections seen in elevational view in Figure 6A.
• the control members are tubular metallic crimps, but as mentioned above may be provided in different configurations.
• FIGs 7A and 7B schematically illustrate a technique for delivering an annuloplasty ring having the core member 100 in a minimally-invasive manner.
• the ring may be opened up or stretched out relatively straight in a stressed state as seen in Figure 7A and inserted within a tubular access device 120.
• the access device 120 may be inserted through an access port in the patient's chest, for example, so that its distal end is positioned at the tricuspid annulus.
• the core member 100 is seen being expelled from one end of the access device 120 in Figure 7B and immediately assuming its relaxed unstressed state.
• the core member 130 includes a braided cable 132 extending from a first free end 132a to a second free end 134b. A number of discrete control points or members 136, 138, 140, 142, 144 are spaced apart along the cable 132.
• the cable 132 In its relaxed state as shown, the cable 132 is in the shape of a Physio IITM Tricuspid Annuloplasty Ring soon available from Edwards Lifesciences, and includes a waveform shape with up and down regions and two upturned free ends 134a, 134b.
• each control member 136, 138, 140, 142, 144 includes a length of wire or cable wrapped helically around the cable 132.
• the wrapped wires perform the same function as the crimped metallic tube and provide both rigidity and shape to the core member 130.
• control points or members may be formed in a number of ways other than the crimped tubes and wrapped wires shown above. It is important to understand that the terms "control point” or “control member” refer to short rigid regions (regions of high modulus) on the otherwise relatively flexible (low modulus) ring. The goal of providing a number of discrete rigid regions is to add rigidity and control the final ring shape, which would be difficult with a purely flexible cable. These control points might, for example, be precise spot-welds on the cable ring, or small steel pins crimped or wrapped around a section of cable and bent to the desired curvature.
• control points may be provided by tubular crimps, wound wires, welds, splices, silver solder, heat fused areas, or spot welded regions.
• Other possibilities include a polymer overmolded around the cable or even certain adhesives that are durable enough to withstand the repetitive flexing motion of the annuloplasty rings.
• a flexible cable, stiffened by control points, provides the ring with sufficient flexibility to compress for delivery through a catheter, while maintaining rigidity in the deployed state. This gives designers valuable freedom, in that materials and cross section can be selected based on cost/familiarity; cable strand count and control points, rather than inherent material properties, are the key design variables.
• control points serve to both create the permanent 3D geometry in an otherwise flexible cable, and to locally modify the flexibility of the ring within a given region, allowing asymmetric deflection under the cardiac cycle to be designed into the product.
• One example of materials is a cable from FWM 1058 Elgiloy, 7x19 strand arrangement, .062" diameter, with short tubular Elgiloy crimps.
• Figures 9-12 and 13-16 illustrate the results of computer simulations of both closed and open rings when certain out-of-plane forces are applied with different control points.
• the graph of Figure 26 was created by tracking the displacement of the posterior commissure (found to deflect the most) over a range of modulus values.
• the relationship between the observable modulus and the maximum displacement can be broken down into three functionally different zones:
• Zone 1 referred to as the "pure cable” zone, represents the region of low modulus values characteristic of cable.
• the specific modulus used in this simulation is the Bending Modulus, which is different than the tensile modulus (known as the Elastic Modulus or Young's Modulus).
• the Bending Modulus for cable is significantly less than for solid-core wire, (hence its greater flexibility).
• a cable will deflect more than a solid-core wire, due to its lower bending modulus.
• one can change the allowable maximum displacement by selecting cables with different alloys, diameter, or strand count to achieve the desired modulus value. By knowing that lower modulus values correspond to greater maximum displacements, one can select an appropriate cable for a given application.
• Zone 3 referred to as the "pure solid-core” zone, represents the region of high modulus values that are characteristic of solid-core wire. When given the same loading conditions as a ring made of cable, a solid-core ring will experience much less overall displacement. In addition, since solid-core wire does not have the inherent flexibility of cable, deformation that occurs will likely be permanent (when compared to cable).
• Zone 2 referred to as the "hybrid” zone, represents high potential interest as the intermediate region where rings can be manufactured to take advantage of the overall flexibility of pure cable, but maintain areas of structural rigidity seen in solid-core wire.
• low-modulus cables can be "adjusted" to an effective modulus which is greater than their native modulus by introducing control points - point-welds along the ring that can be assumed to have a local modulus that resembles a solid-core wire. Since areas of "pure cable” remain between these control points, the ring will still exhibit much of the same flexibility as pure cable. As more control points are introduced, the ring will exhibit a higher effective modulus until it eventually approximates the modulus of a solid-core wire (this would be the case with an infinite number of control points).
• This hybrid region represents the "tunable" range one can utilize by introducing point welds into the cable ring rather than selecting a different material, different thickness, or different strand count. By choosing appropriate locations for these control points, the deformation allowed in each plane can be controlled in addition to the maximum limit.
• Figures 9A shows the relaxed shape of a flexible ring 150 having no control points
• Figure 9B shows the ring shape 12 after having been subjected to the three vertical force arrows shown
• Figure 10A is a ring 154 with two control points 156
• Figure 10B is the shape 158 after loading with the three vertical forces.
• Figures 11 and 12 continue the progression with more control points 162, 168, and the resulting shapes under load are seen decreasing in Figure 11B and 12B.
• the most obvious trend throughout this study is that as more control points are added, the overall displacement of the ring decreases. Localized displacement tends to decrease the most around areas where control points are added as seen between Figures 10B and 11B.
• control points Since adding more control points will inherently form a ring that is more representative of a solid-core ring, we expect that overall displacement will decrease for each additional control point added.
• the important message to take away here is that, by controlling the placement and amount of control points, one can design a cable ring that has regions of controlled displacement.
• the control points are analogous to points on a spline curve, where each point controls how the line curves.
• Figures 13-16 show open or C-shaped tricuspid rings having none, one 186, two 192, and three 198 control points.
• the corresponding simulated loaded shapes are seen in Figures 13B, 14B, 15B and 16B.
• the C ring displacement model was very similar to the D model previously described, except that a different loading scheme was used. Instead of 4 independent forces acting on the ring, as seen in the previous model, the C ring model only used one force in the z plane. In reality, one would expect to see the two free ends of the C ring exhibit some displacement since they are sutured to the aortic root and thus part of the contracting heart. However, these ends were modeled as constraints to simplify the model and focus primarily on the effects of adding control points to the C ring as it is pulled down on the anterior end, as seen in Figures 13B, 14B, 15B and 16B.
• the force created by the cardiac cycle was represented by a single force pulling the ring down in the negative z-axis from the anterior end.
• the force magnitude used was 0.6 N, a little more than half of the anterior force created by the mitral valve.
• the same modulus values described for the D model, for pure cable and for the control point regions, were used for the C model.
• Figures 17A-17G show a number of different braided wire configurations that may be used. These include: a simple 1x3 cable in Figure 17A, a simple 1x7 cable in Figure 17B, and a simple 1x19 cable in Figure 17C.
• Multi- stranded cables include multiple braided cables braided with one another, and include: a 7x7 cable in Figure 17D, a 7x19 cable in Figure 17E, a 19x7 cable in Figure 17F, and a 7x7x7 cable in Figure 17G.
• Each of these cables comprises many individual strands that are twisted around each other whereas solid-core wire is composed of a single strand.
• multi- stranded cables are believed better suited for the MIS delivery approach.
• simple cables may be easily stretched linearly for passage through an access tube, but once permitted to relax and resume the annuloplasty ring shape, these simple cables may not have the requisite stiffness for annulus remodeling. As such, a greater number of control points would have to be used, which may place undesirable limitations on overall ring performance.
• simple cables formed into closed rings may not be able to be squeezed into a linear shape without kinking into permanent bends.
• multi- stranded cables are more flexible in bending due to their generally smaller individual strands and the ability of those strands to slide with respect to one another. Moreover, in open rings multi- stranded cables retain larger stiffness in the plane of the ring to provide good remodeling without an excessive number of control points.
• FIG. 11 illustrates the experimental setup. A minimum bending diameter was determined visually, by bending the cable sample back upon itself until either permanent deformation occurred or cable strands began to separate. At this orientation, measurements were taken by a caliper. The force required to hold this minimum bending diameter was estimated by manually applying the necessary load while the cable was resting on a laboratory scale.
• Results in Table 3 may be sorted to identify good (G), acceptable or fair (F), and poor (P) values with respect to the features necessary for use in MIS Annuloplasty Rings.
• the ideal characteristic is for a cable to be sufficiently flexible to compress for delivery through a catheter, yet maintain rigidity in the deployed state. Given this, samples that had a minimum bending diameter of ⁇ 10 mm were considered good, while those with a minimum bending diameter of >20 mm were considered poor. While force to maintain this bending diameter is not a direct measure of cable bending modulus, it is a reasonable indirect measure; for this reason, an arbitrary value of >400g was considered good, while ⁇ 200g was considered poor.
• One noticeable result was that low- strand-count cables (#7 & #8), were considerably less robust compared to the higher strand count cables.
• a flexible cable stiffened by control points, provides the ring with sufficient flexibility to compress for delivery through a catheter, while maintaining rigidity in the deployed state.
• Prototypes have been constructed employing this strategy (low modulus + sufficient control points to stiffen the ring). It is also possible to combine multiple cable types to achieve the combination of high bending for deployment as well as high post-deployed stiffness.
• FIGs 18A-18C are side, posterior, and top plan views, respectively, of an alternative flexible open mitral annuloplasty ring 220 with control points.
• the annuloplasty ring 220 includes a flexible multi-stranded cable 222 having two free ends 224. In the illustrated embodiment the free ends 224 have been capped or rounded with solder, for example.
• Two side control points 226 and a single posterior control point 228 provide stiffness and shape to the ring 220.
• the control points 226, 228 are shown as crimps, though as mentioned other constructions are possible. [0095]
• the control points 226, 228 of the annuloplasty ring 220 are somewhat longer than previously illustrated.
• the length of the control points in any of the rings described herein may range from between about 3-50 mm, with a preferred range of between about 10-30 mm.
• FIGs 19A-19C are side, posterior, and top plan views, respectively, of a still further alternative flexible open annuloplasty ring 230.
• the annuloplasty ring 230 includes a flexible multi-stranded cable 232 having two free ends 234 that have again been capped or rounded with solder, for example.
• two side control points 236 and a single posterior control point 238 provide stiffness and shape to the ring 230.
• the control point 238 is slightly shorter than the control point 228 in Figures 18A-18C, which renders the ring 230 more flexible than the ring 220.
• Figures 20A-20C illustrate another flexible open
• annuloplasty ring 240 having a flexible multi- stranded cable 242 and free ends 244.
• This ring 240 includes two side control points 246 as before, but instead of one, two posterior control points 248.
• the separation of the two posterior control points 248 leaves a length 250 of cable 242 along the minor axis of the ring, which may be desirable as a flex point.
• one advantage of the flexible annuloplasty rings described herein is their ability to elongate and be delivered through a catheter, or access tube.
• Current annuloplasty ring on the market are made of a single solid wire or laminated strips formed into the desired three- dimensional C or D geometry.
• One major limitation of using solid-core wire is that these types of rings cannot easily be manipulated. For example, a surgeon would not be able to squeeze a D-shaped solid ring to the point where two sides meet for insertion through a small (less-invasive) incision. In order to perform less invasive procedures, these rings must eventually have the ability to be inserted through smaller and smaller openings, and ideally being able to deploy through an 18 French catheter.
• Such a catheter for a minimally-invasive surgery will be relatively short so as to be able to reach from outside the patient's chest through the left atrium to the mitral valve, or via the right atrium to the tricuspid valve.
• the multi-stranded cable rings desirably provide the same functionality as the previous solid-core rings, but can also be manipulated in a way that would enable such less invasive surgical procedures.
• Figures 21A-21D illustrate a distal end of an exemplary tubular delivery system 300 in which an open annuloplasty ring 302 of the present application passes through an access tube 304, such as a catheter.
• a guide wire 306 connects to a distal tip 308 of the annuloplasty ring 302 and when pulled (or held in place while the ring is pushed) deflects the distal tip as it emerges from the tube 304.
• the annuloplasty ring 302 has resiliency and ultimately tends towards its relaxed shape as seen at 310 in Figure 2 ID, even in the absence of a guide wire.
• the guide wire 306 acts as a positioner to guide the distal tip 308 in a particular direction. In this way, the surgeon can orient the final relaxed form of the annuloplasty ring 310 in the annulus plane. Once the annuloplasty ring 302 has been sutured to the annulus, the surgeon detaches the guide wire 306 and removes it in conjunction with the access tube 304. Although not shown, a pusher is typically used to urge the annuloplasty ring 302 from the distal end of the tube 304.
• an open annuloplasty ring 322 emerges from the distal end of an access tube 324.
• a guide wire 326 attaches to a distal tip 320 of the annuloplasty ring 322 and directs the distal tip in a particular direction when relatively held or pulled.
• the guide wire 326 passes through a midportion 330 of the ring 322 so as to deflect the distal tip 328 to a greater extent (smaller bend radius) than the system of Figures 22A-22C.
• the ring assumes its relaxed shape 332 as seen in Figure 22C when it emerges completely from the tube 324.
• FIGS 23A-23C illustrate a still further alternative tubular delivery system 340 for deploying an open annuloplasty ring 342 from within a tube 344.
• a corkscrew-shaped guide wire 346 is initially position within the tube 344, and then a short length is expelled from the distal tip as seen in Figure 23 A.
• the guide wire 346 has a helical, corkscrew waveform which mirrors the 3-D contour of the annuloplasty ring 342. As the ring for 342 is pushed and rotated from within the tube 344, it coils around the guide wire 346. The curvature of the guide wire 346 positions the annuloplasty ring 342 as it deploys. Once the ring 342 has been fully deployed around the guide wire 346, it is sutured into the annulus and the guide wire and access tube 344 are removed from the implantation site.
• FIG 24 is a partial sectional view of a still further alternative annuloplasty ring delivery system 360 wherein a closed annuloplasty ring 362 is expelled by a pusher 364 from a two-part delivery tube 366, 368.
• a proximal portion 366 of the delivery tube may be somewhat flexible to enable a certain amount of bending during delivery to the implantation site.
• the distal portion 368 is somewhat more rigid so as to support loads imparted on the inner lumen due to compression of the annuloplasty ring 362 and friction during deployment.
• the two tubular portions 366, 368 may be formed of different polymer materials that are heat bonded together at their junction, or the rigid distal portion 368 may be metallic. Those of skill in the art will understand that a variety of materials and junctions are possible.
• Figure 25 is a schematic view of the distal end of an alternative tubular delivery system 380 in which an annuloplasty 382 of the present application is deployed by peeling away one side of a delivery tube 384.
• a thin filament or ripcord 386 may be provided in the side of the delivery tube 384 which can be peeled away, thus forming an axial opening 388.
• the annuloplasty ring 382 Because of the resiliency of the annuloplasty ring 382, it eventually expands from its elongated delivery shape into its relaxed final ring shape.
• One advantage of this delivery system 380 is that they are no frictional pushing or sliding forces resulting from relative motion of the ring and catheter during deployment, as with the earlier embodiments, and thus the end of the access tube 384 need not be so rigid.

Landscapes

• Health & Medical Sciences (AREA)
• Cardiology (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Transplantation (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Vascular Medicine (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Prostheses (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (2)

Family

ID=45698225

Family Applications (1)

Country Status (6)

Cited By (3)

Families Citing this family (30)

Citations (1)

Family Cites Families (185)

• 2011
  • 2011-08-24 CA CA2808885A patent/CA2808885C/en active Active
  • 2011-08-24 WO PCT/US2011/049006 patent/WO2012027500A2/en active Application Filing
  • 2011-08-24 US US13/216,472 patent/US10524911B2/en active Active
  • 2011-08-24 BR BR112013004115-3A patent/BR112013004115B1/pt active IP Right Grant
  • 2011-08-24 EP EP11820614.3A patent/EP2608743B1/de active Active
  • 2011-08-24 CN CN201180051179.8A patent/CN103179920B/zh active Active
• 2013
  • 2013-02-05 US US13/759,928 patent/US9326858B2/en active Active
• 2016
  • 2016-04-29 US US15/143,332 patent/US10182912B2/en active Active
• 2019
  • 2019-01-04 US US16/239,899 patent/US10940003B2/en active Active
• 2021
  • 2021-03-08 US US17/195,249 patent/US20210251755A1/en active Pending

Patent Citations (1)

Also Published As

Similar Documents

Legal Events